Lubricating oil composition



United States Patent O LUBRICATING OIL COMPOSITION Norman E. Lemmon, Whiting, Ind., and Ellis K. Fields,

Chicago, IlL, assignors to Standard Oil Company, Chicago, Ill., a corporation of Indiana No Drawing. Application September 8, 1955 it Serial No. 533,254

6 Claims. (Cl. 252-4237) This invention relates to a novel lubricating oil composition and, more particularly, pertains to a lubricating oil composition having improved anti-rust properties and detergency characteristics.

Many oils are not well suited as lubricants for use in internal combustion engines, particularly of the type operating under severe conditions, since under such condi tions the lubricants are susceptible to deterioration res'ulting in the development of carbonaceous and/or resinous or similar varnish-like deposits in the engines and on and about the valves and rings of the engine.

It has heretofore been discovered that certain reaction products of a phosphorus sulfide and a hydrocarbon, particularly an olefin oran olefin polymer, when added in small amounts to a hydrocarbon oil, are effective in inhibiting the formation of varnish, sludge, carbon and the like in lubricating oils during use. It has also been found that neutralizing these reaction products of a phosphorus sulfide and a hydrocarbon with a basic reagent having a metal constituent provides a composition which is effective as a detergent. I v i However, it has been found that under certain conditions lubricants containing the neutralized, metaLcontaining' reaction product ofa phosphorus sulfide and a hydrocarbon do not effectively inhibit the formation of rust and the like on metal surfaces which are being lubricated. It is an object of thepresent invention to provide alubricant for internal combustion engines which. will inhibit such rust formation. It is a further object of the invention to provide a lubricant additive which also serves the functions of (1) inhibiting. the oxidative deterioration of the lubricant, (2) preventing corrosion of the lubricatedsurfaces, and (3) acting as a detergentto prevent ring sticking, varnishing or-coating of the metallic surfaces of. internal combustion engines, as well as a suspending or dispersing agent for: dispersing very small particles of deterioration products or contaminating mate rials in the oil. These andadditional objects willbecome apparent as the description of the invention proceeds.

We have discovered that a product having the desired carbon and/or varnish formation inhibiting properties as well as improved corrosion inhibiting properties and detergent properties can be obtained by incorporating in a lubricant composition atminor proportion, from about 0.001% to about 10% by Weight, and preferably from about 0.1% to about 5% by weight, of the product obtained by reacting, at a temperature of from about 180 F. to about 280 F., from about 80% to about 99% by weight of a neutralized, metal-containing phosphorus sulfide-hydrocarbon reaction product and from about 1% to about 20% of an organic amine compound.

While the reaction product of any of the hereinafter described amines and a neutralized, metal-containing phosphorus sulfide-hydrocarbon reaction product is eifective in increasing the detergency and anti-rust properties ofa lubricating oil, it is not to be implied that all are equally eifective since the effectiveness can vary with the type of lubricating oil and the conditions of use.

2,907,713 Patented Oct. 6, 1959 As aforesaid, the organic amine compound is reacted with a neutralized, metal-containing phosphorus sulfidehydrocarbon reaction product. The hydrocarbon constituent of this reaction product is preferably a monoolefin hydrocarbon polymer resulting from the polymerization of low molecular weight mono-olefinic hydrocarbons or iso-mono-olefinic hydrocarbons such as propylfrom about 150 to about 50,000'01' more, and preferably from about 500 to about 10,000; Such polymers can be obtained, for example, by the polymerization in the liquid phase of a hydrocarbon mixture containing mono-olefins and isomono-olefins such asbutylene and isobutylene at a temperature of from about -80 F. to about 100 F.

' ,inthe presence of a metal halide catalyst of the Friedel- Crafts type such as, for example, boron fluoride, aluminum chloride and the like. In the preparation of these polymers we may employ, for. example, a hydrocarbon mixture containing isobutylene, butylenes and butanes recovered from petroleum gases, especially those gases produced in the cracking of petroleum oils in the manufacture of gasoline.

A suitable polymerfor the reaction with phosphorus sulfide is the product obtained by polymerizingin the liquid phase a hydrocarbon mixture containing butylenes and isobutylenes together with butanes and some C and C hydrocarbons at a temperature between about 0 F. and 30 F. in the presence of aluminum chloride. A suitable method for carrying out the polymerization is to introduce thealuminum chloride into the reactor and introduce the hydrocarbon mixture cooled to a temperature of about 0 F. into the bottom of the reactor and pass it upwardly through the catalyst layer while regulating the temperature Within. the reactor so that the polyperature of about 30 F. After separating the polymer merproduct leaving the top of the reactor is at a temfrom the catalyst sludge and unreactedhydrocarbon, the polymer is fractionated to obtain a fraction of the desired viscosity such as, for example, from about 80 seconds to about 2000 seconds Saybolt Universal at 210 Another suitable polymer is that obtained by polymerizing in the liquid phase a hydrocarbon mixture comprising substantially C hydrocarbons in the presence of an aluminum chloride-complex catalyst- The catalyst is preferably prepared by heating aluminum chloride withisc roctane. The hydrocarbon mixture is introduced into the bottom of the reactor and passed upwardly through the catalyst layer, while a temperature of from about. 50 F. to about F. is maintained in the reactor. The pro pane and other saturated gases pass through the catalyst,

mass is neutralized, washed free of acidic substancesajnd the unreacted hydrocarbons subsequently separated from the polymers by distillation. The polymer mixture so obtained, depending upon the temperature of reaction, .varies inconsistency from a light liquid to a viscous, oily material, and contains polymers having molecular weights ranging from about 100 to about 2000 or higher. The polymers so obtained may be used as such, or the polymer may be fractionated under reduced pressure into fractions of increasing molecular weights, and suitable fractions reacted with the phosphorus sulfide to obtain the desired reaction products. The bottoms resulting from the fractionation of the polymer may have Saybolt Universal viscosities at 210 F. ranging from 50 seconds to about 10,000 seconds and are well suited for the purpose of the present invention.

Essentially paraffinic hydrocarbons such as bright stock residuums, lubricating oil distillates, petrolatums, or paraffin waxes may be used.- There can also be employed the condensation products of any of the foregoing hydrocarbons, usually through first halogenating the hydrocar bons and then reacting with'aromatic hydrocarbons in the presence of anhydrous inorganic halides, such as aluminum chloride, zinc chloride, boron fiuoride and the like.

Examples of high molecular weight olefinic hydrocarbons which can be employed as reactants are cetene (C cerotene (C melene (C and mixed high molecular alkenes obtained by cracking petroleum oils.

Other preferred olefins suitable for the preparation of the herein-described phosphorus sulfide reaction products are olefins having at least 20 carbon atoms in the molecule of which from about 13 carbon atoms to about 18 carbon atoms, and preferably at least 15 carbon atoms, are in a long chain. Such olefins can be obtained by the dehydrogenation of paraflins, such as by the cracking of paraffin waxes, or by the dehydrohalogenation of alkyl halides, preferably long chain alkyl halides, particularly halogenated paraffin waxes.

The olefins obtained by dehydrohalogenation of long chain alkyl halides are preferably those obtained by dehydrohalogenation of mono-halogenated waxes, such as for example, those obtained by dehydrochlorination'of monochlor paraflin wax. The alkyl halides are decomposed to yield olefins according to the relation.

I n 2n+1 n 2n+ in which n is a whole number, preferably 20 or more, and

X is a halogen. It is preferred to employ paraflin waxes having at least about 20 carbon atoms per molecule, and melting points upwards from about 90 F. to about 140 F. e

To obtain the halogenated paraflin wax, for example, chlorinated parafiin wax, chlorine is introduced into the wax, maintained in a molten state, until the wax has a chlorine content of from about 8% to about 15%. The chlorinated wax product is a mixture of unchlorinated wax, monochlor wax and polychlor wax. This chlorinated product may be used as such, but it is advantageous to use the substantially monochlor wax fraction. The monochlor wax fraction can be segregated from the unchlorinated wax and the polychlor wax fractions by taking advantage of the differences in the melting points of the various fractions, since the melting point of the wax varies with the extent of chlorination, i.e., the melting a 4 removing the chlorine from the latter as hydrogen chloride. The monochlor wax can be dehydrochlor'inated by heating to a temperature of from about 200 F. to about 600 F. in the presence of a dehydrochlorinating agent such as an alkali metal hydroxide or an alkaline earth metal hydroxide or oxide. Other alkaline inorganic or organic materials can also be used. The chlorine can also be removed from the chlorowax by heating the same for a prolonged period in the absence of any dehydrochlorinating agent. After the dehydrohalogenation has been completed, the olefin so obtained can be further purified by removing the dehydrohalogenating agent by means of filtration or by other suitable means.

As other starting materials there can be used the polymer or synthetic lubricating oil obtained by polymerizing unsaturated hydrocarbons, resulting from the vapor phase cracking of paraffin waxes, in the presence of aluminum chloride, which is fully described in United States Patents Nos. 1,955,260, 1,970,402 and 2,091,398. Still another type of olefin polymer which may be employed is the polymer resulting from the treatment of vapor phase cracked gasoline and/or gasoline fractions with sulfuric acid or solid absorbents such as fullers earth whereby unsaturated polymerized hydrocarbons are removed. Also contemplated within the scope of this invention is the treatment with phosphorus sulfide of the polymers resulting from the voltolization of hydrocarbons as described, for example, in United States Patents Nos. 2,197,768 and 2,191,787.

Also contemplated within the scope of the present invention are the reaction products of a phosphorus sulfide with an aromatic hydrocarbon such as for example benzene, naphthalene, toluene, xylene, diphenyl and the like, or with an alkylated'aromatic hydrocarbon such as, for example, benzene having an alkyl substituent having at least four carbon atoms and preferably at least eight carbons atoms such as, for example, long chain parafiin waxes, olefin polymers and the like.

The phosphorus sulfide-hydrocarbon reaction product can be readily obtained by reacting a phosphorus sulfide, for example, P 5 with the hydrocarbon at a temperature of from about 200 F. to about 500 F. and preferably from about 200 F. to about 400 F., using from about 1% to about 50% and preferably from about 5% to about 25% of the phosphorus sulfide in the reaction. Itisadvantageous to maintain a non-oxidizing atmosphere such 'as, for example, an atmosphere of nitrogen above the reaction mixture. Usually it is preferable to use an amount of the phosphorus sulfide that will completely react with the hydrocarbon so that no further purification becomes necessary; however, an excess amount of phosphorus sulfide can be used and separated from the product by filtration or by dilution with a solvent suchas hexane, filtering and subsequently removing the solvent by suitable means such as by distillation. If desired, the reaction product can be further treated with an agent having an active hydrogen atom such as steam at an elevated temperature of from about 1005 F. to about 600 F. The phosphorus sulfide-hydrocarbon reaction product normally shows a titratable acidity which is neutralized by treatment with a metal-containing basic reagent. The phosphorus sulfide-hydrocarbon reaction product when neutralized with a basic reagent containing a metal;con stituent is characterized by the presence or retentionof the metal constituent of the basic reagent. Other metal constituents such as a heavy metal constituent can be introduced into the neutralized product by reacting the same with a salt of the desired heavy metal. The term neutralized metal-containing phosphorus sulfide-hydrocarbon reaction product as used herein means a phosphorus sulfide-hydrocarbon reaction product having at least about 1% of its titratable acidity neutralized by reaction with a basic reagent and includes the neu tralized phosphorus sulfide-hydrocarbon reaction products tralization or resulting from thereaction of a heavy metal salt with the phosphorus sulfide-hydrocarbon reaction product treated with a basic reagent.

The neutralized phosphorus sulfide-hydrocarbon reaction product can be obtained by treating the reaction product with a suitable basic compound such as a hydroxide, carbonate, oxide or sulfide of an alkaline earth metal or an alkali metal such as, for example, potassium hydroxide, sodiumhydroxide, sodium sulfide, etc. The neutralization of the phosphorus sulfide-hydrocarbon reaction product is carried out preferably in a non-oxidizing atmosphere by contacting the reaction product either as such or dissolved in a suitable solvent such as naphtha With a solution of the basic reagent, for example, potassium hydroxide or sodium hydroxide dissolved inalcohol. As an alternative method, the reaction product can be treated with solid alkaline compounds such as KOH, NaOH, Na C K CO CaO, Na s, and the like at an elevated temperature of from about 100 F. to about 600 F. As was aforesaid, when the phosphorus sulfide-hydrocarbon reaction product is neutralized with a basic reagent containing a metal constituent, the neutralized reaction product is characterized by the presence of the metal constituent of the basic reagent. Neutralized reaction products containing a heavy metal constituent such as, for example, tin, titanium, aluminum, chromium, cobalt, zinc, iron, and the like, can be obtained by reacting a salt of the desired heavy metal with the phosphorus sulfide-hydrocarbon reaction product which has been treated with a basic reagent. It will be understood that when the neutralization is accomplished with a polyvalent basic material such as lime, a product having excess basicity may be obtained.

The neutralized, phosphorus sulfide-hydrocarbon reaction product can also be prepared by the method described in U.S.2,688,612, issued to Watson onSeptember 7, 1954.

The organic amine compound employed in preparing the additive of the present invention can be an aliphatic amine, an aliphatic polyamine, an aromatic amine, an aromatic polyamine, or compounds in which nitrogen forms part of a ring such as, for example, pyridine, quinoline, pyrimidine, morpholine, etc. Particularly suitable aliphatic amines are those containing from about 8 to about 24 carbon atoms such as, for example, octa decyl amine. Secondary and tertiary aliphatic amines may also be used. Suitable aliphatic polyamines include those having the general formula RNH(CH NI-I in which R is preferably a C to C aliphatic chain, and which are obtained by condensing the suitable amine with acrylonitrile and hydrogenating to the corresponding diamine. Commercially available polyamines of this type are those marketed by Armour & Company as Duomeens which are prepared by the-condensation of a dodecyl (coco) amine or an octadecyl (tallow) amine with acrylonitrile followed by hydrogenation to the corresponding diamine product; these products are marketed as Duomeen C and Duomeen T, respectively. We may also employ aromatic amines such as aniline, substituted anilines, or the like. It is also contemplated within the scope of this invention to employ aromatic polylarliiines, such as, for example, phenylenediamine or the The amines may be chemically pure products or of a commercial quality. We have found as desirable aliphatic amines the amines obtained in thefollowing process; fatty acids, derived from natural fatty acid glycerides, are converted into nitriles and the nitriles are reduced,

principally to primary amines at temperatures below 150 6 'C. and under alkaline conditions. Depending upon the fatty acid employed, the aliphatic amines usually contain from about 8 to about 18 carbon atoms. Suitable amines are the products manufactured according to this general procedure and sold by Armour & Company under the 6 trade name Armeen, such as Armeen 2C, Armeeii CD, Armeen SD, Armeen 8D, Armeen 12D, Armeen 14D, etc. Other amines which are suitable are the Primenes manufactured and sold by the Rohm & Haas Company. These are mixtures of substantially primary amines having molecular weights of from about 185 to 353 and are prepared according to the following procedure: a nitrile such as formonitrile or acetonitrile is reacted with an olefin such as tetra-propylene or tetra-isobutylene, or mixtures of such olefins,,inthe presence of concentrated sulfuric acid. The resulting N-substituted amide is hydrolyzed with'caustic; the amine is separated and distilled.

In accordance with the present invention, the hereinbefore described amines and neutralized metal-containing phosphorus sulfide-hydrocarbon reaction product are reacted at a temperature from about 180 F. to about 280 F. and preferably from about 200 F. to about 240 F. The amount of amine relative to the amount of phosphorus sulfide-hydrocarbon reaction product is in the range of from about 1% to about 20% by weight and preferably in the range of from about 3% to about 10% by weight. The reaction is carried out for a period of time of from about 5 minutes to about 1 hour, or more, and preferably for a period of time of about 15 minutes. A reaction period of substantially greater length than this has no appreciable beneficial eifect and is economically The amine may be reacted directly with hydrocarbon reaction product with a lubricating oil having desirable properties before reacting the organic amine compound.

As pointed out hereinbefore, compositions containing our additive have excellent anti-rust characteristics. Tests were made to demonstrate this effect using the following compositions Example A.SAE 10 solvent extracted base oil containing 2.50% of a barium-containing neutralized P 8 butene polymer (mean molecular weight of about 940 and viscosity of about 3,000 SUS at 210 F.) reaction product.

Example B.--Example A reacted with 0.25% by weight (based on weight of oil) of primary octadecyl amine at 230 F. for 15 minutes.

These tests were carried out as follows: open hearth low carbon steel panels approximately 2 x 3 x V inches are uniformly abraded by sandblasting, dipped in the test f composition and the excess allowed to drain, then immersed in distilled water at F. The panels are examined periodically to see when rust spots appear. If

rusting is severe, the water becomes colored yellow from rust. The results are shown in Table I.

Other examples of our invention are shown in Table II. These examples were prepared asfollows:

Examples C--I.-SAEv 30 solvent extracted base oil containing 5.44% of a barium-containing, neutralized P 8 butene polymer (mean molecular weight of about 940 and viscosity of about 3,000 SUS at 210 F.) reaction product was reacted with the indicated weight percent of the indicated amine at 220 F. for 15 minutes.

Two tests were used to demonstrate the effectiveness of our composition. The test identified as D -665 in Table II is an A.S.T.M. test for determining rust prevent 'ing characteristics of oil in'the presence of water. This test is described in full in the 1949 book of A.S.T.M. standards, part 5, pages 967-971. In addition to AS.

"7 T.M. test D-665, a film tenacity test was made on each of the compositions shown in Table II. This test is run immediately after A.S.T.M. D-665 and is similar 'in all respects except that the oil used in the test is removed and replaced with water. As its name implies, this test indicates the tenacity of the oil film on the test specimen.

As may be readily seen by inspection of Table II, all

'of the amine reaction products tested provide excellent anti-rust properties.

Inasmuch as it has been suggested previously that a composition containing a mixture of a phosphorus sulfidehydrocarbon reaction product and an amino compound ;would provide a lubricant having detergent and anticorrosion properties, some of the amine compounds indicated in Table II were added to the base oil containing the barium-containing, neutralized phosphorus sulfidebutene polymer reaction product without reacting at a those shown in Table II indicates the unexpected effectiveness obtained by reacting the organic amine compounds with the phosphorus sulfide-hydrocarbon reaction 'product rather than by merely mixing the same together.

Concentrates of a suitable lubricating oil base containing from about 10% to about 50% or more of the hereindescribed additive, alone or in combination with various :amounts of other additives, can be used for blending with 'other hydrocarbon lubricating oils or other lubricating oil bases in the proportion desired for the particular conditions of use to give a finished product containing from about 0.001% to about 10% of our additive.

'carboxylic acid ester type oils such as the oil-soluble esters of adipic acid, sebacic acid, azelaic acid, etc. It is also contemplated that various other of the well known corrosion inhibitors, antioxidants, anti-foaming agents, pour point depressors, extreme pressure agents, anti-wear agents, V.I. irnprovers, etc. may be incorporated in lubricating oils containing the additive of our invention.

Unless otherwise stated, the percentages stated herein and in the claims are weight percentages.

Although the present invention has been described with reference to specific preferred embodiments thereof, the invention is not to be considered as limited thereto, but includes within its scope such modifications and variations as come within the spirit of the appended claims.

We claim:

1. A lubricant composition having improved anti-rust and detergency properties comprising a major proportion of a lubricating oil and in combination therewith a minor proportion, from about 0.001% to about 10% by weight, of the product obtained by reacting at a temperature of from about 180 F. to about 280 F., from about 80% to about 99% by weight, of a neutralized, metal-containing phosphorus sulfide-olefin hydrocarbon reaction product and from about 1% to about 20% by weight of an organic amine compound selected from the class consisting of an aliphatic hydrocarbon amine, an aromatic hydrocarbon amine and a heterocyclic amine having from about 4 to about 9 carbon atoms in the heterocyclic ring, said neutralized, metal-containing phosphorus sulfideolefin hydrocarbon reaction product being obtained by reacting from about 15 to about by weight phosphorus sulfide with an olefin hydrocarbon at a temperature from about 200 F. to about 500 F. and neutralizing the resulting product with a basic compound of a metal selected from the group consisting of alkali metals and alkaline earth metals.

Table II '[SAE 30 base 011 plus 5.44% of a barium containing P s -butene olymer reacted for 15 minutes at 220 F. with the indicated amineil Amine Con D-665 Rust Film Tenac- Pereent ity, Rust Example 0 N,N-Dibutyl aniline o. 542 gloderate.

0. 54 Example D Primene 81-R 0. 272 0. 0.136 slight.

0. 544 0. Example E Armeen 14-D 0.272 0.

0.136 very slight. 0. 544 Example F Armeen 20 0, g Slight 0.5 Example G Dnomeen T 0.272 0.

0. 136 very slight. Example H 1-octadecyl-2.5-dimethyl 0. 544 0.

pyrrolldiue. 0. 272 very slight. vExample I Octadecylamine 0. 544 V 0.

Control- None- 0 Severe Severe Table III [SAE 30 base 011 plus 5.44% of a barium containing P ss-bntene olymer mixed at ambient v 7 temperature with the indicated amineg Amine 0011., D-665 Rust Film Tenac- Percent ity, Rust Example I Primene 81-R 0. 544 very slight slight. Example K- Armeen 2C 0. 544 very slight.-. very slight. Example L l-octadecyl-2,5-dlmethyl 0. 544 s1ightpyrrolidine. V

While the present invention has been described by the carbon oils, natural or synthetic, such as those obtained by the polymerization of olefins, as well as synthetic 2. The composition of claim 1 wherein said neutralized, metal-containing phosphorus sulfide-hydrocarbon reaction product is a neutralized, barium containing, phosphorus sulfide butene polymer reaction product.

3. The composition of claim 1 wherein said organic lubricating oils of the alkylene oxide types, and the polyamine compound is an aliphatic amine.

4. The composition of claim 1 wherein'said organic amine compound'is a heterocyclic nitrogenous base compound.

5. The composition of claim 1 wherein said organic amine compound is an aromatic amine.

6. The composition of claim 3 wherein said aliphatic amine is an aliphatic polyamine.

References Cited in the file of this patent UNITED STATES PATENTS Mikeska May 2, Hill July 7, Beegle Mar. 6, Jones a- Aug. 21, 

1. A LUBRICANT COMPOSITION HAVING IMPROVED ANTI-RUST AND DETERGENCY PROPERTIES COMPRISING A MAJOR PROPORTION OF A LUBRICATING OIL AND IN COMBINATION THEREWITH A MINOR PROPORTION, FROM ABOUT 0.001% ATO ABOUT 10% BY WEIGHT, OF THE PRODUCT OBTAINED BY REACTING AT A TEMPERATURE OF FROM ABOUT 180* F. TO ABOUT 280* F., FROM ABOUT 80% TO ABOUT 99% BY WEIGHT, OF A NEUTRALIZED, METAL-CONTAINING PHOSPHORUS SULFIDE-OLEFIN HYDROCARBON REACTAION PRODDUCT AND FROM ABOUT 1% TO ABOUT 20% BY WEIGHT OF AN ORGANIC AMINE COMPOUND SELECTED FROM THE CLASS CONSISTING OF AN ALIPHATIC HYDROCARBON AMINE, AN AROMATIC HYDROCARBON AMINE AND A HETEROCYCLIC AMINE HAVING FROM ABOUT 4 TO ABOUT 9 CARBON ATOMS IN THE HETEROCYCLIC RING, SAID NEUTRALIZED, METAL-CONTAINING PHOSPHORUS SULFIDEOLEFIN HYDROCARBON REACTION PRODUCT BEING OBTAINED BY REACTING FROM ABOUT 15 TO ABOUT 50% BY WEIGHT PHOSPHORUS SULFIDE WITH AN OLEFIN HYDROCARBON AT A TEMPERATURE FROM ABOUT 200* F. TO ABOUT 500* F. AND NEUTRALIZING THE RESULTING PRODUCT WITH A BASIC COMPOUND OF A METAL SELECTED FROM THE GROUP CONSISTING OF ALKALI METALS AND ALKALINE EARTH METALS. 